Rotor blade mounting arrangement

ABSTRACT

The arrangement is described in use in a gas compressor which is of the axial flow type, having a plurality of stages of compression, and an overhung rotor. A housing and frame enclose and support the working elements of the compressor, the elements being so supported and enclosed as to allow for relative movements of the housing without causing distortion of said elements. The arrangement comprises blade mounting rings, for emplacement on a rotor shaft, in which the rotor blades are pivotally pinned. Further, each blade has a recess and a tang, at opposite sides thereof, for receiving a tang and recess, respectively, of adjacent blades, to accommodate for relative vibratory movement therebetween. Also, vibration dampening elements are interleaved between adjacent blades.

United States Patent [191 Canova et a1.

ARRANGEMENT [75] Inventors: Fred Canova, Phillipsburg; Leroy M. Krouse, Easton; Hanns Hornschuch, Easton; Paul Hermann, Easton, all of; Joseph A. Dopkin, Hopewell, NJ.

[73] Assignee: lngersoll-Rand Company, New

York, NY.

[22] Filedi Aug. 1, 1973 [21] Appl. No.: 384,451

Related US. Application Data [62] Division of Ser. No. 235,501. March 17, 1972, Pat.

No. 3,773,430. I

[52] 11.5. C1. 416/215, 416/500 [51] Int. Cl. B64c 27/48, F04d 29/34 [58] Field of Search ..4l6/134,212,215,217, 416/500 [56] References Cited UNITED STATES PATENTS 2.405.146 8/1946 Huber 416/217 2.664240 12/1953 Gorton 2.955.799 10/1960 Oickle. Jr. 416/500 ROTOR BLADE MOUNTING [451 Nov; 26, 1974 3,292,900 12/1966 Pettersen 416/500 3,752,598 8/1973 Bowers et a1. 415/217 FOREIGN PATENTS OR APPLICATIONS 706,618 3/1954 Great Britain 416/212 750,397 6/1956 Great Britain 416/500 Primary ExaminerI-1enry F. Radua zo Attorney, Agent, or Firm-Bernard .1. Murphy 5 7 ABSTRACT The arrangement is described in use in a gas compressor which is of the axial flow type, having a plurality of stages of compression, and an overhung rotor. A housing and frame enclose and support the working elements of the compressor, the elements being so sup.- ported and enclosed as to allow for relative movements of the housing without causing distortion of said elements. The arrangement comprises blade mounting rings, for emplacement on a rotor shaft, in which the rotor blades are pivotally pinned. Further, each blade has a recess and a tang, at opposite sides thereof, for receiving a tang and recess, respectively, of adjacent blades, to accommodate for relative vibratory movement therebetween. Also, vibration dampening elements are interleaved between adjacent blades.

1 Claim, 4 Drawing Figures .2. O O Q e a O O 16 52 I O 28 48 i H "7%: 90 32 ea 32 52 I 24 \i 30 I 40 1 1" 1 72 2o 5a 34 38 30 36 32 I 74 as 82/ $81 TKIG 74 1 y 22 HEP I 11, in" 1 4 n PATimggasvzslsm sum 30F 5 ROTOR BLADE MOUNTING ARRANGEMENT This is a division of application Ser. No. 235,501; filed Mar. 17, 1972, now US. Pat. No. 3,773,430.

This invention pertains to rotor blade mounting arrangements for use in gas compressors, and in particular to gas compressors of the axial flow type where rotor blades are subject to vibration-induced failures.

It is an object of this invention to set forth a rotor blade mounting arrangement which especially accommodates for vibratory movement of rotor blades. Especially is it an object of this invention to teach means for dampening relative vibratory movement between rotor blades.

Another object of this invention is to setforth an arrangement for mounting rotor blades on a rotor shaft, for use in a gas compressor, comprising a blade mounting ring, said ring having a central aperture for engagement with and about the periphery of a rotor shaft, and means for receiving a rotor blade therewithin; at least one rotor blade, having a mounting head on one end thereof, wherein said mounting head and said blade mounting ring have boreholes formed therethrough for receiving means for pivotally securing said blade to said mounting ring; and said mounting head further has means on at least one side thereof for nesting a vibration-dampening element thereat in contacting engagement with said one side.

Further objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying figures, in which:

FIG. 1 is an axial view, partly in cross-section, of an rotor blades mounting arrangement in use in a embodiment of a gas compressor, according to the invention;

FIG. 2 is an enlarged view of a detailed area of FIG. 1; and

FIGS. 3 and 4 are side and end views illustrative of the rotor blade and mounting ring arrangement.

As shown in the FIGURES, the novel gas compressor comprises a housing 12 having a base 14 for supporting the housing thereupon. A pair of oppositely disposed gas inlet flanges 16 are mounted to each side of the housing, the flanges defining inlet ports 18 which open on a chamber 20 defined within the housing. At the axial outlet end of the compressor is mounted a gas discharge flange 22 having an outlet port 24 formed therein.

Upstream of the inletend are carried coupling means and a bearing housing assembly (not shown), the two being supported in a casing 26 which is fixed to the compressor base 14. An over-hung, axially-extending rotor and shaft assembly 28 is rotatably supported at but one axial end in the bearing housing, for rotary, gas-compressing movement within a compression chamber 30, and includes pluralities of radiallydisposed blades 32. A vaned stator 34, concentrically disposed about the rotor and shaft assembly, is mountedly supported within the compressor housing, by means of a cylindrical housing 36 which carries vane mounting rings 38 therewithin. The stator 34 comprises a plurality of such vane mounting rings in juxtaposition, each of which has fixed therein a plurality of vanes 40. All of the vanes 40 are of uniform length; however, the stator mounting rings 38 are of uniformly varying crosssection, from the inlet end to the outlet end of the compression chamber so that, toward the outlet end, progressively less of the vanes 40 protrudes into the compression chamber 30. Each vane 40 is pinned into its respective mounting ring 38.

The housing base 14 comprises a vertical plate 46 which has passageways (not shown) formed therein for the admittance of ambient atmosphere as a sealant and also for introducing lubricating oil. Also, the lubricating oil is conducted by drilled passageway 48 from annular seals 50,50a set about the shaft of the rotor and shaft assembly 28 and subsequently drains into the beating housing assembly.

The rotor and shaft assembly 28 comprises a plurality of juxtapositioned blade mounting rings 52, each of the rings having a plurality of the blades 32 mounted therein and radially extending away therefrom. Each blade 32 at the head end thereof has a forked extension 54 which is bored through to receive a pin 56. Further, each blade mounting ring has a plurality of boreholes 58 formed therethrough for retaining opposite ends of the blade-retaining pins. Each blade, at the head end thereof, has a laterally extending tang 60 which protrudes into a complementary, interfacing recess 62 provided therefor in an adjacent blade head end. Finally, the forked extensions 54 of adjacent blades have cooperative, arcuate cut-outs 64 formed therein with an elastomeric insert 66 therebetween. The pinning of the forked extensions, and the elastomeric inserts, cooperate to allow the blades to swing through a small arc to accommodate for vibration.

The rotor shaft has a hollow extension 68 about which the rotor blade mounting rings 52 are mounted.

At the outlet end of the gas compressor is disposed a diffuser shell 72 which is open at both, opposite, ends. One end is in direct open communication with the outlet end of the compression chamber 30, and the end opposite opens directly onto the outlet port 24. One end, the outlet end of this diffuser shell, is retained by a circumferential shoulder 74 formed within the outlet flange and about the outlet port. The diffuser shell outlet end and the circumferential shoulder have a compliant, sealant medium 76 therebetween. Further, the compressor housing has a radially and inwardly extending weldment 78 which abuttingly receives a radial ring 80 formed about and extending from the diffuser shell,

said weldment and ring having an O-ring seal 82 therebetween.

Another ring 84 is welded within the outlet end of the housing, intermediate the weldment 78 and the outlet end of the diffuser shell 72, to present a flat-surface annulus for slidably supporting the diffuser shell therewithin. Four ribs 86 (only one is shown), equally spaced therebetween about the rotor axis, are fixed at either ends thereof to the annulus of ring 84 and the weldment 78 to provide further support for the diffuser shell therewithin and for the outlet end of the compressor.

The blade mounting rings 52 of the rotor, and the vane mounting rings 38 of the stator as well, are each independently replaceable. The innermost blade mounting ring (i.e., the one nearest the inlet end of the compression chamber) is set up against a circumferential shoulder 88 formed in the outer surface of the rotor shaft extension 68. Successive adjacently-disposed blade mounting rings 52 are set against the innermost one, along the shaft axis. The last or outermost blade mounting ring is secured on the rotor shaft extension by a retainer plate 90 bolted (by means not shown) to the shaft extension.

The novel rotor blade mounting arrangement herein described in connection with a compressor, due to the independent replaceability of the blade mounting rings 52, renders maintenance and repair easy, and accommodates a facile re-rating of the compressor. Simply by replacing given outermost mounting rings with dummy rings or spacers, or by wholly substituting differentlydimensioned and/or configured blades in replacement mounting rings,-- the performance of the compressor can be altered.

While we have described our invention in connection with a specific embodiment thereof, it is to be clearly understood that this is done only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the appended claims.

We claim:

1. An arrangement for mounting rotor blades on a rotor shaft, for use in a gas compressor, comprising:

a blade mounting ring, said ring having a central aperture for engagement with and about the periphery of a rotor shaft, and means for receiving a rotor blade therewithin;

at least one rotor blade, having a mounting head on one end thereof; wherein said mounting head and said blade mounting ring have boreholes formed therethrough for receiving means for pivotally securing said blade to said mounting ring; and

said mounting head further has means on at least one side thereof for nesting a vibration-dampening element thereat in contacting engagement with said one side; wherein said mounting head has a single tang projecting therefrom, at a first side thereof, and a single tang receiving recess formed in a side thereof opposite to said first side, for effecting an interengagement of said latter single tang and recess with a recess and tang, respectively, of mounting heads disposed in adjacency thereto; and

said nesting means comprises an arcuate, substantially semi-circular cut-out; and further including a pivot pin in penetration of both said mounting head and said blade mounting ring boreholes; and

a second rotor blade having a mounting head on one end thereof; wherein said second rotor blade is pivotally pinned to said blade mounting ring, in immediate adjacency to said one rotor blade; and I said second rotor blade mounting head has an arcu-' ate, substantially semi-circular cut-out formed therein which cut-out aligns with, and defines a substantially fully circular void with, said arcuate cut-out in said mounting head of said one rotor blade and resilient means nested within said device for maintaining said single tang and recess in a normal spaced apart relationship relative to a respective recess and tang disposed in adajcency thereto, and for damping vibration of said one and said second rotor blades.

" UNITED STATES PATENT OFFICE fiERTIFICATE OF CORRECTION Patent No. 3,850,547 Dated 26 November 1974 inventor) Fred Canova, et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the first page of the patent, the INID Code [75] information should read:

-Fred Canova, Wellsville, N.Y. Leroy M. Krouse,

Hanns Hornschuch, and Paul Hermann, all of Easton, PA'.; Joseph A. Dopkin, Hopewell, NJ--;

In column 4, line 26, "device" should read --void--.

Signed and sealed this 6th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. An arrangement for mounting rotor blades on a rotor shaft, for use in a gas compressor, comprising: a blade mounting ring, said ring having a central aperture for engagement with and about the periphery of a rotor shaft, and means for receiving a rotor blade therewithin; at least one rotor blade, having a mounting head on one end thereof; wherein said mounting head and said blade mounting ring have boreholes formed therethrough for receiving means for pivotally securing said blade to said mounting ring; and said mounting head further has means on at least one side thereof for nesting a vibration-dampening element thereat in contacting engagement with said one side; wherein said mounting head has a single tang projecting therefrom, at a first side thereof, and a single tang receiving recess formed in a side thereof opposite to said first side, for effecting an interengagement of said latter single tang and recess with a recess and tang, respectively, of mounting heads disposed in adjacency thereto; and said nesting means comprises an arcuate, substantially semicircular cut-out; and further including a pivot pin in penetration of both said mounting head and said blade mounting ring boreholes; and a second rotor blade having a mounting head on one end thereof; wherein said second rotor blade is pivotally pinned to said blade mounting ring, in immediate adjacency to said one rotor blade; and said second rotor blade mounting head has an arcuate, substantially semi-circular cut-out formed therein which cutout aligns with, and defines a substantially fully circular void with, said arcuate cut-out in said mounting head of said one rotor blade and resilient means nested within said device for maintaining said single tang and recess in a normal spaced apart relationship relative to a respective recess and tang disposed in adajcency thereto, and for damping vibration of said one and said second rotor blades. 